The photochromism of 1,2-bis-(3-thienyl)-cyclopentene derivatives involves the reversible photoinduced cyclization between the colorless-open and the colored-closed forms of the chromophore1. This phenomenon is interesting for its potential role in optical materials and photonic devices such as variable-transmission filters, optical information storage systems and photo-regulated molecular switches2. The need for practical handling of definite forms of photochromic materials such as films, sheets, fibers or beads, dictate the use of polymeric rather than monomeric photochromes3,4. Homopolymers (i.e. polymers derived from one species of monomer) are more desirable than copolymers as they will have an increased density of the photochromic unit within the material. This translates into a greater amount of information expressed or stored per unit volume or surface.
Existing polymerization processes rely on harsh reaction conditions which limits the structure of photochromic products. The present invention employs very mild reaction conditions which allows compatibility and flexibility, including the capacity to synthesize products having a variety of pendant functional groups. The chemistry can be controlled and therefore macroscopic properties may be tailored.
In view of the foregoing, there is a need in the art to develop novel photochromic homopolymers and methods of synthesizing same.